boulder, the Mason-bee of the Walls is always glad to make use of the
old nests which have lasted through the year without suffering any
damage worth mentioning. The mortar dome has remained very much what
it was at the beginning, thanks to the solidity of the masonry, only
it is perforated with a number of round holes, corresponding with the
chambers, the cells inhabited by past generations of larvae. Dwellings
such as these, which need only a little repair to put them in good
condition, save a great deal of time and trouble; and the Mason-bees
look out for them and do not decide to build new nests except when the
old ones are wanting.

From one and the same dome there issue several inhabitants, brothers
and sisters, ruddy males and black females, all the offspring of the
same Bee. The males lead a careless existence, know nothing of work
and do not return to the clay houses except for a brief moment to woo
the ladies; nor do they reck of the deserted cabin. What they want is
the nectar in the flower-cups, not mortar to mix between their
mandibles. There remain the young mothers, who alone are charged with
the future of the family. To which of them will the inheritance of the
old nest revert? As sisters, they have equal rights to it: so our code
would decide, since the day when it shook itself free of the old
savage right of primogeniture. But the Mason-bees have not yet got
beyond the primitive basis of property, the right of the first
occupant.

When, therefore, the laying-time is at hand, the Bee takes possession
of the first vacant nest that suits her and settles there; and woe to
any sister or neighbour who shall henceforth dare to contest her
ownership. Hot pursuits and fierce blows will soon put the newcomer to
flight. Of the various cells that yawn like so many wells around the